The results are based both on research and driver surveys. In the survey part, 74% of drivers in the UK said that with satellite navigation in the car, they felt more in control and 55% said they felt more alert (9% said they felt less alert). It wasn't clear if the survey asked questions such as, "I worry that I'm distracted glancing too often at the display, or when the dog kicks out the power cord." There was, however, a finding that 59% of drivers (UK again) said they found it easier to keep their attention on the road.

Instrumented findings: 11% less wasted time
Using instrumented vehicles, research groups at TUV/DLR in Germany and at Virginia Tech Transportation Institute observed less distraction and a lower "workload" with a navigation system than using conventional maps or Web-based maps and trip planners. The U.S. research found the most dangerous actions and unsafe driving were in vehicles without navigation.

The instrumented test vehicles also found that when navigating to an unknown destination "compared to navigation by conventional means" (apparently maps and stopping at gas stations to ask directions), miles traveled dropped by 6.5% and time spent fell by 11.2% (in Germany).